Electric phonograph record and method of making the same



. 1,620,122 March 1927' A. MUTSCHEILLER ELECTRIC PHONOGRAPH RECORD AND METHOD OF MAKING THE SAME Filed May 1. 1923 8 =f=1rsuR El VII/II, ylmwlulllm k I I FJEURE: 4. =FJEURE E1 4 J 1 12 H 1 J6 J? 16 r. v 6 x gig 13 V 32 ll" 34 I 1EURE E INVENTOR 21 48 J/rf/zur fiutsc/wller 46 BY 14/ m; ATTORNEY.

Patented Mar. 8, 1927.

' UNITED STATES PATENT OFFICE.

ARTHUR MUTSCHELLER, OF NEW YORK, N. Y.

ELECTRIC PHONOGRAPH RECORD AND METHOD OF MAKING THE SAME.

Application filed May 1, 1923. Serial No. 635,868.

well known as phonographs, graphophones,

gramophones, talking machines and the like, and also in telegraphones, machine telephones, and automatic telephone transmitters for wire lines and wireless systems.

My invention is in fact well adapted for use in practically all relations where sounds are to be produced, reproduced, imitated or transmitted, through the agency of a record subjected to the direct action of an electric current, for the purpose of controlling or being controlled by the latter.

More particularly stated, my invention comprehends the construction and action, as well as the method of making, of a phonographic record provided with an operating surface, the ohmic resistance of which is different at different points along said surface, and so distributed as to so vary the flow of an electric current through the record; the electric current thus affected being used in connection with a telephonic receiver or equivalent device, for the purpose of producing sounds.

Heretofore records have been usually in, the form of either a disk or a cylinder, and made of wax, resin, hard rubber, or some one of a number of well known compositions suitable for the purpose. Upon each record is cut, by means of a recording stylus provided with a sharp cutting edge or point, a groove of undulatory form, the precise form of the groove being controlled by vibratory motions of a diaphragm with which the stylus is connected.

The groove may be cut either vertically or laterally. The record being completed and ready for use in the production of sounds, a different form of stylus, connected with a reproducing diaphragm, is next rested upon the groove, and the record is then moved relatively to the stylus, so that the stylus is actuated and the reproducing diaphragm caused to vibrate and thus to produce sounds.

For the good reproduction of certain sounds, andparticularly those having very high frequencies of vibration, it has heretoin this art phonographic fore been necessary to apply considerable pressure to the reproducing stylus in order to enable it to follow faithfully the undulatory variations of the groove. It has been found, however, that in order to render the pressure adequate for the purpose here contemplat ed, undue friction is set up between the record and the reproducing stylus, and on this account the normal work of the stylusis interfered with, and there is a production of undesirable sounds intermingled with the sounds which the reproducer is intended to produce. Again, it is found in practice difficult to vary the intensity of the sounds reproduced in the manner just men- .tioned, for the reason that various factors,

including the degree of pressure between the stylus and the record, if suitably apportioned for vibrations of one mean frequency, are unsuitable for vibrations of a different mean frequency. The difficulties just described, and many others not mentioned but well known in this art, I seek to overcome by means of my invention.

Reference is made to the accompanying drawing forming a part ofthis specification, and in which like reference characters indicate like parts throughout the several figures.

Figure 1 is a substantially central fragmentary vertical section through a phonograph equipped with a disk record made in accordance with my invention.

Figure 2 is a fragmentary section corresponding to a portion of Figure 1, but upon a larger scale and showing the record grooves and a stylus used in connection therewith.

Figure 3 is a fragmentary section extend ing lengthwise of a portion of the record groove. I

Figure 4 is a fragmentary section showing a different form of my improved record from that appearing in the other figures.

Figure 5 is a diagram of an electric circuit used in connection with the making of the record, this circuit including a microphone.

Figure 6 is a diagrammatic section of a receiver to be used in reproduction, and which for this purpose may be substituted for the microphone shown in Figure 5.

Figure 7 shows my improved record as used with an electric circuit differing from that shown in Figure 5, and including a vacuum tube amplifier as well as a microphone.

A phonograph 8, which may be of the usual or any desired construction is provided.

with a-turntable 9, the latter being mounted upon a revoluble shaft 10, driven by gearing 11. The turntable carries a mat 12.

Resting upon the mat 12 and thus'revoluble with the turntable is a record 13, made in accordance with one form of my in-- vention.

The record 18 is made of sheet metal provided with a facing 14, this facing being made of composition as hereinafter described, and provided with a record groove 15. Engaging the facing 14 and fitting lightly into the record groove 15 is a stylus 16, made of metal which is non-corrosive for the purposes hereinafter described, and is preferably silver, but may be one of many other metals.

The facing 14 is made up in a number of different ways, some of which are set forth below.

As the basic material for the facing I select a substance which can be reduced to a fine powder, though not necessarily impalpable. This substance should have considerably higher ohmic resistance than that of a metal, and should be one upon which it is possible to deposit, by electrolysis, a firmly-adhering coat of metal. thus selected, after being reduced to powder as aforesaid, is mixed with a suitable binder, which should be insoluble in water and of such character as not to interfere with the subsequent deposit, by electrolysis, of metal upon and into the pores of, the basic material. There may be used as the basic material either graphite, silundum, silfrax, etc.,

and as the binder there may be used a small proportion of sodium silicate. The basic material in the form of a powder and the sodium silicate also in the form of a powder, are wet up and worked together in the form of a paste which is then spread out or molded and dried, and thus hardened, so as to form the facing 14. Still another method would consist in admixing an electrolyte solution, as hereinafter described, before the hardening.

Another way to make the facing 14 1s.to reduce the basic material to powder, as before, mix with it a binder of organic material in the form of a plastic mass or a powder, wetting the entire mass and working it up into a paste, then spreading out or molding this paste into the form of a record facing, and finally heating the article thus produced, in order to break up the organic material and thus leave a porous facing such as 14. Gelatine, pitch, resin, wheat flour, etc., are typical of the organic substances which may be used as binders. Preferably the groove 15 should be made by impressing the plastic mass before it is dried and hardened.

The substance The construction of the record disk being finished, the facing 14, which is porous, is now wet thoroughly with an electrolytic solution, of a kind suitable for electro-plating. An example of such an electrolytic solution is argentocyanide solution, such as is commonly employed for depositing silver.

F or an electrolytic liquid for the purposes here contemplated, a salt giving monovalent ions is preferable to a salt giving polyvalent ions.

In connection with this solution and other electrolytic solutions for depositing silver, I preferably make the stylus 16 of pure metallic silver. It may, however, be made of any other metal or conducting substance such as will remain clean when brought into contact with the solution under the conditions here contemplated. The metal of the stylus and the metallic ion of the electrolyte should preferably be of the same element.

In some instances I make the record as indicated in Figure 4, the recorddisk 17 being provided with a facing 18. Inthis case the facing is made up of astructural mass, the various particles actually touching each other. With this facing the deposit of silver can be rendered more nearly uniform throughout the porous mass, so' that there,

are formed an infinite, number of paths differing essentially from each other in ohmic resistance, due to the varying deposits of metal along the various paths. T

In some instances the record disk may be very smooth, so that itspore's are not noticeable, and covered with a liquid electrolvt containing a metal, thestvlus not touching the surface of the disk, but spaced therefrom by an infinitesimal distance and thus trailing through the electrolyte. In this instance the metal deposited by electrolyt action does not extend to an appreciable distance downinto the'mass of the record disk and to all intents and purposes the deposit is upon the outer surface'of the disk,

, but varies in thickness.

The electric circuit is arranged as indicated in Figure 5. A wire 19 leads from the shaft 10 to a microphone 20. From the microphone a wire 21 leads to a rheostat 22.

From the rheostat a wire 23 leads to a battery 24 or other appropriate source of electric current flowing in one direction only, and from this battery or its equivalent a wire 25 leads to the stylus 16. The-flow of current through the record is in the direction indicated by the plus and minus signs to acoustical action the electric'current flowing through the circuit indicated in this 13, shaft 10, wire 19, microphone 20, wire 21, rheostat 22 and wire 23 back to battery 24.

The current flowing in the circuit just described acts upon the electrolytic fluid contained within the pores of the facing 14, and causes a deposit of metallic silver to take place. This deposit of silver is-not in the form of a coating, as this term is generally used. It is rather in the form of innumerable patches, individually too small to be seen by the naked eye, and in the aggregate appearing as discolorations. The

deposits of metallic silver thus made have the effect of varying within wide limits the ohmic resistance of the facing 14, the resistance of the latter being least where the deposits are greatest, and vice versa. The acoustical exercise or rendition affecting the microphone being finished, the turntable is stopped and the record removed and dried out, so as to remo e all residual portions of the electrolytic liquid. This completes the record and makes it ready for use.

In some instances, and particularly when .it is desirable to obtain a wide range in the quantity of metal deposited in different portions of the record facing, I employ the arrangement shown in Figure 7. A vacuum tube amplifier 26, such as is commonly designated 'in this art an audion, a pliotron, a radiotron or the like, is provided in the conventional manner with a glower filament 27, a grid 28 and a plate 29. A wire 30 leads from the filament 27 to the stylus 16. A rheostat 31 is connected with the filament 27 and wire 30, and from the rheostat 31 a Wire 32 leads to a battery 33 or equivalentsource of electric current. From the battery 33 a wire 34 leads to a wire 35, the latter being connected with the microphone 20. A wire 36 is connected with the wires 34 and 35 and with the filament 27. A wire 37 leads from the grid 28 to a rheostat 39, and from the latter a wire 39 leads to a battery 40 or its equivalent. From this battery a wire 41 leads to the micro phone 20. A wire 42 leads from the plate- 29 to a battery 43 or its equivalent, and fromthis battery 44 leads to the shaft 10.

In this arrangement a circuit for heating the filament may be-traced as follows: battery 33, wire 32, rheostat 31, filament 27, wire 36' and Wire 34 back to battery 33.,

Another circuit, through the filamentand plate of the vacuum tube and through the record facing, may be traced as follows battery 43, wire 42, plate 29, filament 27, wire 30, stylus 16, record 13, shaft 10, and wire 44, back to battery 43.

of reproduction,

The receiver employed is shown in Figure'6. Mounted within the casing 45-15 a magnet 46 and a diaphragm 47. The casing is provided with a horn 48. This receiver may be substituted for the micro: phone 20 shown in Figure 5. For this purpose the Wires 19 and 2l'are disconnected from the microphone 20, and are connected with the magnet 46,, but in case of the wiring of Figure 7, the telephone is connected instead of the phonograph plate, and the phonograph plate and stylus is connected,

where the microphone is shown in Figure 7.

In order to use the phonographic record, prepared as above described, for purposes the record facing 14 acts as a variator for the current flowing through it and through the receiver, so that thereceiver reproduces the sounds originally made in the microphone.

I do not limit myself to the precise mechanism here shown, :as variations may be made therein without departing from my invention, the scope of which is commensurate with my claims.

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent is as follows: v

l. The method, herein described, of producing phonograph records tobe used for v'a-' 95 r in t is intensit of electric currents which consists in producing a record member hav-v ing a porous texture and having an ohmic resistance considerably greater than that of silver, causing said record member toabsorb andhold within its pores an electrolyte con taining a metal, subjecting said record member, thus carrying said electrolyte in its pores, to the action of an electric current and continuously shifting thepoint of ap- 1 plication of said electric current relatively to said record member, for the purpose of depositing metal into the pores of said record member, and finally removing the excess of electrolyte contained within the pores of the facing.

2, The method, herein described, of preparing phonograph records to be used for varying the intensity of electric currents, which consists in preparing a record member having a porous texture and holding in its pores an electrolyte containing a' metal, said record member having an ohmic resistance higher than that of said metal, sending an electric current continuously through said excess of electrolyte from the pores of the record member.

:3. The method, herein described, of preparing phonograph records to be used for varying electric currents, which consists in preparing a record member having a high ohmic resistance and provided with pores, causing said record member to absorb and hold within its pores an electrolyte containing silver, applying to said record member an electrode provided with a point made of silver and engaging said record, continuously shifting the position ofsaid record member relatively to said electrode, and continuously supplying to said record, through said electrode, an electric current of varying intensity, for the purpose of causing silver to be deposited in unequal quantities in the pores of diiferent portions of said record member.

1 means for turning the same, a facing carried by said revoluble member, said facing having pores and holding in said pores by ab sorption an electrolyte containing a metal,

an electric circuit connected with said facing for the purpose of depositing within said pores said metal from said electrolyte, and means for energizing said surface by an electric current having intensity variations analogous to sound waves.

5. A device of the character described, comprising a porous record member containing in its pores an electrolytic solution for the purpose of depositing conducting material into said pores, an electric circuit connected with said porous record member for the purpose of subjecting to electrolytic action the electrolyte contained in said pores, means for continuously varying the strength of the said electric current after the manner of the varying intensity of sound waves, and amplifying mechanism included within said circuit for the purpose of amplifying the variations in the quantity of conducting material thus deposited in said pores.

6. The method herein described of preparing phonograph records for varying the intensities of electric currents, which consists in providing a record member capable of carrying an electrolyte containing a metal and provided with pores, bringing such electrolyte into'contact with said record member, sending an electric current through said electrolyte and through said record member so as to make a metallic deposit upon said record member, and to fill up said pores, and amplifying variations in the electric current thus sent through said electrolyte and said member, so as to amplify the thickness of the metal thus deposited by electrolytic action.

7. The method, herein described, of preparing phonograph records to be used for varying the intensity of electric currents, which consists in producing a record memher having a porous texture and having a relatively high ohmic resistance, causing said record member to hold within its pores an electrolyte containing a metal, subjecting said record member, thus carrying said electrolyte in its pores, to the action of an electric current, and continuously shifting the point of application of said electric current relatively to said record member.

8. In a device of the character described the combination of a record member having a facing provided with pores and holding in said pores by absorption an electrolyte containing a metal, and means for applying an electric current to consecutive portions of said facing, for the purpose of depositing within said pores said metal from said electrolyte.

Signed at Long Island City, N. Y., inthe county of Queens and State of New York, this 18th day of April 1923.

ARTHUR MUTSCHELLER. 

